Improvement in printing-telegraphs



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J. E. SMITH. Printing Telegraphs. N0.I57,8 80. Patented Dec.15,1874.

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1. E. SMITH.

Y Printing Telegraphs. I

No.l57,880. Patented Dec.15,1874.

wifzaixes; I I Z fi JOHN E. SMITH, on new YORK, n. Y.

IMPROVEMENT IN PRlNTlNG-TELEGRAPHS.

Specification forming part of Letters Patent No. 15?,880, dated December 15, 1874; application filed November 12, 1873. I

To all whom it may concern Be it known that I, JOHN E. SMITH, of the city, county, and State of New York, have invented an Improved Attachment to the Main Circuits of Printing-Telegraphs, of which the following is a specification:

This invention is designed for use in connection with printing-telegraph instruments whose type-wheel magnets and printing-magnets are constantly located in and form part of the same main circuit; and it consists in the location, in such circuit, of a resistance-coil or rl1e0- stat and an eleetro-magnet, whose armaturelever, by a prolonged current on the stoppage of the type-wheels, is made to shunt said coil or rheostat, thereby augmenting the line-wire current sufficiently to actuate the printingmagnets.

Figure 1 represents a side elevation of my improved apparatus or attachment; Fig. 2, a

plan of the same, and Fig. 3 an end view thereof. Fig. 4 is a plan of an apparatus in combination with a main circuit and one ofa series or any number of ordinary printing telegraphic instruments in the same circuit.

Similar letters of reference indicate corresponding parts.

Upon any suitable base, A, is mounted an electro-magnet, B, whose soft-iron armature C is attached to a lever, D. This lever, when moved by the magnet B, is stopped by an insulated set-screw, E, and is checked by a set screw, F, when withdrawn from the magnet B by a retracting-spring, G. H is a resistance coil or medium, one terminal, b, of which connects with the insulated set-screw E, and the other terminal, 0, with a binding screw, I. This resistance may be of any wellknown variable or adjustable form-such, for instance, as any rheostat employed in electrical measurements, in order that it may be easily varied according to the number of printers in circuit with it. One end, d, of the Wire of magnet B connects with the screw E, while the other end, 0, of the same is clamped by the binding-screw J. The lever D is put in direct electrical communication with bindingscrew I by means of a wire, K. The instrument is located in the main circuit by the wires of the latter connecting with the bindin g-screws IJ.

properly adjusted and located in a main circult of printingtelegraph instruments whose printing-m agnets form part of such circuit, and said circuit is provided with battery not quite powerful enough to actuate the printingmechanism while the current passes through the resistance H, the combination will operate as follows: hile rapid electric pulsations actuate the type-wheel magnets, the shun tin gmagnet B will not become highly enough magn'etized to overcome the retractingspring G; therefore, as the lever D is not in contact with screw E while the type-wheels rotate, all of the current which passes over the line will go through the resistance H as well as magnet B, so that during the rotation of the typewheels the printing portion of the receivinginstruments will remain inactive; but when the current is prolonged by a momentary pause in the circuit-breaker of the transmitter, the magnet B, in consequence of such prolonged current, will become sufficiently energized to move the lever I) into contact with screw E, when the current will pass from E to I, principally by way of the shunt-route D K. By virtue of this reduced resistance in the circuit, the current will instantly become sufficiently augmented to actuate the printing-magnets. Thus the type-wheel magnets are actuated directly by short pulsationsthe shunting-magnet by a prolonged current, and the printing-magnets by an augmented current.

It will be seen that the instrument herein described properly forms no part of a printingtelegraph instrument, nor of the transmitter that but one such instrument is required in a whole line of printers and transmitters; that it may be connected in such a circuit wherever it can be most conveniently supervised;

that it may be used in connection with printing-tclegraphs the same, whether their typewhcels are liberated by electricity or are impelled by the direct action of electromagnetism, whether the electric pulsations are all of one polarity or partly of both polarities, or whether the printing-levers are operated directly by electro-magnets or by mechanism released by electromagnetism.

In Fig. 4 of the drawing, M represents a main circuit with which the apparatus hereinbefore described connects, and in which are any number of printing telegraphic instruments, one only, marked P,here being shown.

I claim as my invention A resistance-coil or Iheostat and a shunting-magnet and connections, substantially as herein described, in combination with a main circuit in which are placed the printing and the type-wheel magnets of any number of telegraph-instruments, for the purpose of making the current for operating the printingmagnets more powerful than is necessary for rotating the type-wheels.

J. E. SMITH.

Witnesses:

MICHAEL RYAN, FRED. HAYNES. 

